Abstract

Superluminescent diodes (SLDs) offer relatively high power over a broad emission spectrum, useful in many applications such as fibre-optic gyroscopes and optical coherence tomography (OCT). A key parameter defining the coherence properties of the SLD is the spectral ripple, or spectral modulation depth, which occurs due to non-zero reflection at the facets of the device. Current methods to suppress this reflection include use of anti-reflection (AR) coatings and tilted waveguides to bring effective facet reflectivity down to ~10⁻⁵. Transparent window regions are commonly used in InP optical amplifiers, which can be combined with AR coatings and tilted waveguides to offer the greatest suppression of Fabry-Perot oscillations, such coating may not cover the wider spectrum which make an absorbing window become a contributing key in our design.

© 2015 IEEE